Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, China.
PLoS One. 2021 Nov 12;16(11):e0260045. doi: 10.1371/journal.pone.0260045. eCollection 2021.
This study evaluated the ability of Aspergillus niger and Trichoderma koningii to improve the quality of tea dregs (TDs) through solid-state fermentation as well as the value of the fermented tea dregs (FTDs) produced for use as bio-feed additives. After fermentation, FTDs differed in color and structure. Fermentation with A. niger and T. koningii increased the contents of crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber of TDs. Compared to the unfermented group, the contents of reducing sugar, total flavonoids, total polyphenols, and theasaponins were increased in A. niger FTDs, while in T. koningii FTDs caffeine was completely degraded, the theasaponins were lower, and the contents of reducing sugar and caffeine higher. Regarding free amino acids, A. niger FTDs had the highest content of total amino acids, total essential amino acids, total non-essential amino acids, total aromatic amino acids, total branched-chain amino acids, and total non-protein amino acids, and all types of essential amino acids, followed by T. koningii FTDs and the control TDs. Fungal fermentation had similar effects on the content of various hydrolytic amino acids as those on above free amino acids, and increased the content of bitter and umami components. The composition of essential amino acids of TDs or FTDs was similar to that of the standard model, except for sulfur-containing amino acids and isoleucine. Solid-state fermentation with A. niger and T. koningii effectively improved the nutritional value of TDs, increased the contents of functional substances, and improved the flavor of TDs. This study demonstrated a feasible approach to utilize TDs that not only increases animal feed resources, but also reduces the production of resource waste and pollution.
本研究评估了黑曲霉和康宁木霉通过固态发酵提高茶渣（TDs）质量的能力，以及所产生的发酵茶渣（FTDs）作为生物饲料添加剂的价值。发酵后，FTDs 在颜色和结构上有所不同。黑曲霉和康宁木霉发酵使 TDs 的粗蛋白、粗纤维、中性洗涤纤维和酸性洗涤纤维含量增加。与未发酵组相比，黑曲霉 FTDs 的还原糖、总黄酮、总多酚和茶皂素含量增加，而康宁木霉 FTDs 中的咖啡因完全降解，茶皂素含量较低，还原糖和咖啡因含量较高。关于游离氨基酸，黑曲霉 FTDs 的总氨基酸、总必需氨基酸、总非必需氨基酸、总芳香族氨基酸、总支链氨基酸和总非蛋白氨基酸含量最高，所有必需氨基酸类型均高于康宁木霉 FTDs 和对照 TDs。真菌发酵对各种水解氨基酸的含量有类似的影响，也增加了苦味和鲜味成分的含量。TDs 或 FTDs 中水解氨基酸的组成与标准模型相似，除了含硫氨基酸和异亮氨酸。黑曲霉和康宁木霉的固态发酵有效提高了 TDs 的营养价值，增加了功能性物质的含量，改善了 TDs 的风味。本研究为利用 TDs 提供了一种可行的方法，不仅增加了动物饲料资源，而且减少了资源浪费和污染的产生。
